/*
* This example is from the book "Java Enterprise in a Nutshell".
* Copyright (c) 1999 by O'Reilly & Associates.
* You may distribute this source code for non-commercial purposes only.
* You may study, modify, and use this example for any purpose, as long as
* this notice is retained. Note that this example is provided "as is",
* WITHOUT WARRANTY of any kind either expressed or implied.
*/
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class LifeCycleServlet extends HttpServlet {
int timesAccessed;
public void init(ServletConfig conf) throws ServletException {
super.init(conf);
// Get initial value
try {
timesAccessed = Integer.parseInt(getInitParameter("defaultStart"));
}
catch(NullPointerException e) {
timesAccessed = 0;
}
catch(NumberFormatException e) {
timesAccessed = 0;
}
// Try loading from the disk
try {
File r = new File("./data/counter.dat");
DataInputStream ds = new DataInputStream(new FileInputStream(r));
timesAccessed = ds.readInt();
ds.close();
}
catch (FileNotFoundException e) {
// Handle error
}
catch (IOException e) {
// This should be logged
}
}
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
timesAccessed++;
out.println("<HTML>");
out.println("<HEAD>");
out.println("<TITLE>Life Cycle Servlet</TITLE>");
out.println("</HEAD><BODY>");
out.println("I have been accessed " + timesAccessed + " time[s]");
out.println("</BODY></HTML>");
}
public void destroy() {
// Write the Integer to a file
File r = new File("./data/counter.dat");
try {
DataOutputStream dout = new DataOutputStream(new FileOutputStream(r));
dout.writeInt(timesAccessed);
dout.close();
}
catch(IOException e) {
// This should be logged
}
}
}
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